Adjustable propeller



Now 8, 1932'. DE WlTT c. CONKLING ADJUSTABLE PROPELLER Filed Jan. 22,1931 4 Sheets-Sheet 1 4-: 1I[ INVENTOR l-ATOR Nov. 8, 1932. DE W|TT c.CONKLING 1,387,145

' ADJUSTABLE PROPELLER Filed Jan. 22, 1951 4 Sheets-Sheet 2 INVENTORNov. 8, 1932. DE WlTT c. CONKLING 1,

ADJUSTABLE PROPELLER Filed Jan. 22, 1951 4 Sheets-Sheet 5 INVENTOR Nov.8, 1932. 01% WlTT c. CONKLING 1,837,146

ADJUSTABLE PROPELLEYR Filed Jan. 22, 1931 4 Sheets-Sheet 4.

into a'feathering or reversed Patented Nov. 8, 1932 PATENT OFFICE DEWITH? 0. CONKLING, 0! LONG ISLAND, NEW YORK ADJUSTABLE PROPELLEBApplication filed January 22, 1931.; Serial No. 510,423.

This invention relates to an peller, and while the invention is capableof use in the construction of propellers for various purposes, it isparticularly adapted for use upon aeroplanes, and the like.

An object ofthe invention is to provide a propeller and operatingmechanism therefor, all constructed and corelated to provide for theeasy and accurate change of pitch of the propeller blades from aremotecontrol as for instance from a control located at the drivers seat in anaeroplane.

A more specific object is to provide against the likelihood of any looseplay of the propeller blades with respect to their mountings andoperating mechanism. A I

A further object is -to provide in combination an adjustable propeller,an engine for driving said propeller, a remote control for thepropeller, and connections between the propeller and the remote controlextending in a substantially straight line through the engine at theaxis of rotation of the propeller.

A further object is to provide an improved,

efiicient and accurate form of control whereby to adjust the blades ofan adjustable propeller.

Afurther object is to rovide means to prevent the accidental ad ustmentof the propeller into a reverse angular position without the definiteintent on the part of the operator so to do. v

A further object is to rovide means for preventing adjustment of t epropeller blades position except when the speed of the engine has beenreduced to desirable degree. 7

A further object is to provide means automatically operable to reducethe engine speed in the ei'ent that efiort is made by the operator toreverse thepropeller blades without having previously manually reducedthe engine speed. p

A further objectis to provide means normally effect-iveto preventattainment of a too great engine speed when the propeller blades are ina reversed position but capable of permitting, manual control of theengine speed to max mum in an emergency.

A further object is to provide means to adjustable propermit starting ofthe engine at low speed irrespective. of the position of the propellerblades but normally efiective to prevent any considerable engine speedexcept when, or until, the propeller blades are in their;normal ornon-reversed position.

A further object is to provide means effective when the blades are in areversed position to limit the speed at which the engine may normally berun in proportion to the angular position of the propeller blades.

A further object is to so construct the control mechanism that it willbe freely operable by the manual manipulation of a single operatinghandle, and so that said handle and hence the propeller blades, willstand definitely in any position to which they are adjusted by theoperator.

A further object is to provide means gperable automatically to changethe pitch 0 the pro eller blades dependent upon the altitude of t eapparatus above the earth.

Other objectsand aims of the invention, more or less specific than.those referred to above, will be in part obvious and in part pointed outin the course of the following escription of the elements, combinations,arrangements of parts and applications of principles constituting theinvention; and the scope of protection contemplated will be Il'ldicatedin the appended claims.

In the accompanying drawings which are to be taken as a part of thisspecification, and in which I have shown merely a preferred form ofembodimentof the invention Fig. l'is a perspective view of-the forwardportion of an aeroplane fitted with a reversible propeller and operatingmechanism therefor constructed in accordance with this invention. I

-Fig.-2 is an enlarged vertical sectional view of the mechanismillustrated in Fig. 1. Fig. 3 is a vertical sectional view approximatelyupon the plane of line I II'1II of Fig. .2, parts being shown inelevation for clearness of disclosure.

Fig. 4 is a top plan view of the hub portion of the blade carrier shownin Fig. 3. v

Fig. 5 is a vertical sectional view illustrat-' ing a modifiedarrangement in which an lit) trating a modified engin nism.

Fig

8 is a vertical sectional view upon the plane of line VIII-VIII of Fig.7, and

Fig. 9 is a diagrammatic development of parts appearing in Figs.' 7 and8.

Referring to the drawings for describing in detail, the structures asillustrated therein, the reference character L indicates the forwardportion of an aeroplane. The propeller drive shaft G projects centrallyfrom the structure L in the usual manner and carries the propellerblades H-H. I

The mannerof connecting the propeller blades with the. shaft which isrigidly connected to the projecting end of the shaft, as by means of aretaining nut 2, the sleeve being held against rotation upon the shaftby a suitable means such as the feathers 3. A pair ofstud shafts as 4and 5 are formed upon this sleeve projecting in diametrically oppositedirections therefrom, being rigid with the sleeve and hence with theshaft G. The propeller blades are mounted upon these stud shafts so asto .be

rotatable within limits upon said shafts. Each propeller blade has asleeve 6 which fits over the respective stud shaft, and asuitableretaining nut or the like as? carried at the outer end of the stud shaftis positioned in opposition to an annular shoulder 8 providedinteriorlygfthe sleeve so that'the sleeve is held by said nut againstmovement endwise of the stud shaft. A suitable anti-friction bearingthrust device as 9 is preferably interposed between the nut and theshoulder 8 to facilitate ease of rotation of the sleeve upon the studshaft under the excessive thrust strains which occur due to centrifugalforce when the propeller blades are being rapidly swung about with theshaft G in use.

If desired each of the sleeves 6 maybe additionally provided with anannular-interior groove 10 to fit about an annular rib 11 of therespective stud shaft for further.

guarding against endwise movement of the sleeve 111 use.

In order to vfac'litate application of the sleeves 6 onto thestudsh'afts said sleeves are herein shown as each beingformed in twogenerally semimylindrical parts held together by clamp devices 12-12.These clamp devices are held in position about the sleeves by means ofsuitable lock nuts or the G includes a sleeve 1.

stance illustrated the pinion as like as 13 and may therefore be readilyattached or removed as may be required to facilitate the attachment andremoval-of the sleeves upon the stud shafts.

The manner of attaching the sleeves upon the ends of the propellerblades H may take I any form but as illustrated herein the sleevesproject beyond the end of the stud shafts 4 and 5 and the propellerblades are clamped between the two halves comprising the projectingportion. The propeller blades have one or more annular ribs as 1athereon re-- ceived within annular grooves 15 interiorly of the sleeves,and additional clamp elements as 16 are positioned about that portion ofthe sleeve which envelopes the blade. It is noted that the portions ofthe sleeves which surround the end of the propeller blades are of suchsize that when the clamp elements 16 are clamped tight upon the sleevethen the halves of the sleeves are likewise tightly engaged upon theblades so that the blades and sleeves are non-rotatable with respect toeach other.

The clamp devices 16 are held by lock nuts or the like 17 and aretherefore readily attachable and detachable to facilitate attachment andremoval of the sleeves from the blades, and from the stud shafts, whenrequired.

The sleeve 6 of each blade is formed at its ilmer end witha segmentalpinion projecting at one side thereof, the teeth being disposedconcentric with the axial center line of the stud shafts. The sleevesare positioned upon their respective stud shafts so that the pin ionsproject in diametrically opposite directions with respect to said centreline. In the in- 18 of the sleeve which is mounted upon the stud shaft 4projects downwardly while the pinion as 19 of the sleeve which ismounted upon the stud shaft 5 projects upwardly.

These segmental pinions 18 and 19 are of course positioned at oppositesides of the axial centre line of the main drive shaft G.

' Slidably mounted upon the shaft Gr, and

preferably upon a tubular extension as 20 of tension 20 by suitablemeans such as the feathers 24 as will be readily understood.

From this arrangement it will be seen that shdingmovement of the sleeve21, operating is positively held through the rack bars and segmentalpinions,

will produce a rotary movement of thepro-.

ller blades-in opposite directions so that the thrust angle of thebladesis thereby readshaft and within this cavity is a pair of coil,

springs as 26-and 27 coiled about the stud shaft. The spring 26 isformed at one-of its ends with a hook 28 which engages about a pair ofpins as 29 and 30. These pins stand normally aligned with each otherradially .of the pin shaft, the pin 29 being carried rigid with the pinshaft 5 and the pin 30 being carried rigid with the sleeve 6, and itwill be noted that the hook 28 is of a width to engage both of said pinsso thatrotary movement of the sleeve 6 for instance in a clock-wisedirection about the shaft 5 will cause the hook to be moved by the pin30 away from the pin 29 thereby tensioning the spring 26, while rotationof the sleeve 6 in the opposite or contraclockwise direction will simplymove the pin 30 away from the hook leaving the hook rest- .ing againstthe pin 29.

The opposite end of the spring 26 is fixed to the shaft 5 as at 31 inany suitable manner, and it will be understood that the spring is at alltimes under a desirable degree of tension.

The spring 27 is formed at one of its ends with a hook as 32 facingcircumferentially in an opposite direction as compared with the hook 28.Thehook 32 engages about a pair of pins as 33 and 34 which standnormally aligned with each other radially of the pin shaft, the pin 33being carried rigid with the pin shaft and the pin 34 being carried'rigid with the sleeve 6. The hook 32 is of a width to engage both ofsaid pins 33 and 34 so that rotary movement of the sleeve 6 for instancein a'contra-clockwise direction about turn said sleeve in one directionand the other the shaft will cause the hook to be moved by the pin 34away from the pin 33 thereby tensioning the spring 27, while rotation ofthe sleeve 6 in the opposite or clock-wise direction will simply movethe pin 34 away from the hook leaving the hook resting against the pin33. i

The opposite end of the spring 27 is fixed to the shaft 5 asat 35 in anysuitable manner, and it will be understood that the spring is at alltimes under a desirable degree of ten- 4 sion.

According to this arrangement the springs 26 and 27 exert resilientpressure in opposite directions against the sleeve 6, one tending totending to turn it in the opposite direction. The pins 29 and 33constitutecentering means by which a normal intermediate position isdefined for the sleeve thereby holding the sleeve against unintentionalrotation upon its carrying shaft 5 and approximately in a position whichis preferably the normal, or most venient position within the areoplane,as for,

instance adjacent the drivers seat, and a flexible driving shaft as 37extending from said handle to adjacent the sleeve 21. The

sleeve 21 has a collar 38 rotatable in an annular groove thereon andformed with suitable lugs 39 which are engaged by yoke arms 40. The arms40 are pivotally mounted upon a pivot shaft 41 at one side of the driveshaft G and have a segmental rack 42 fixed thereto which is engaged by asmall pinion 43 fixed upon a shaft 44. The shaft 44 has a larger pinion45 fixed thereon engaging with the teeth of a worm 46 directly actuatedby the flexible shaft 37.

Rotation of the handle 36 will thus swing the oke arms and thereby movethe sleeve 21 bacl and forth at the will of-the operator.

Reduction gears or other apparatus as may be desired may be interposedbetween the handle 36 and the shaft 37, as indicated at 47, whereby theblades from the handle 36.

In the modification Figs. 5 and 6 the two rack bars 48 and 49,corresponding respectively with the two rack bars22 and 23 heretoforedescribed, instead of being connected with a collar slidable upon the.sleeve 20, are connected with a body piece 50 which is in turn rigidlymounted upon the outer endof a slide rod 51 longitudinally slidablewithin a required to rotate with the engine shaft 3 as is the forwardend portion of said shaft. The f -rtion 57 may be held against rotationat all tunes by suitable means such for instance as by means of thestationary pin 58 slidable through a laterally projecting lug 59 of saidsleeve, the shaft being thus permitted longitudinal movement but withoutrotation.

The inner end of the portion 57 is threaded 'as at 60 and a. threadedcollar 61 engages to facilitate the easy operation 'of 7 51 said shaftis split and is connected together by an anti-friction connection as 56so that its rear end portion as 57 is not thereabout having a gear 62fixed thereto by which it maybe rotated as-by means of the pinion 63which is carried upon the pivot shaft 6& of the handle 55. A suitablymarked stationary dial as 65 may be provided concentric with the pivotshaft 64 to assist the operator in determining the position of hispropeller blades by means of the handle 55, and a sutable frictiondevice as 66 may be carried by the handle for engaging against thesurface of the dialplate to hold the handle against unintentionalmovement at all times.

These parts are allmounted upon a suitable support 67, such as theinstrument board or other stationary element of aeroplane constructionadjacent the drivers seat.

It will be seen that movement of the handle 55 around the dial willrotate the threaded sleeve 61 and thereby move the shaft 51-57 slidablythrough the engine shaft 53 and alter the angularposition of thepropeller blades in one direction or the other according to thedirection, and in the amount, in which the handle 55 has been moved.

The engine 54 may be of any desired construction providing for passageof the slide shaft 51-57 therethrough centrally of the axis of rotationof the propeller blades with the engine shaft, but for the purpose ofillustration herein said engine is'indicated asbeing of the type fullyillustrated and described in pending application Serial No. 477,242which includes essentially a series of power cylinders as 68 radiatingfrom the central drive shaft 53, being carried upon a housing as 69within which the drive shaft is rotatably mounted. Connecting rods as 70project from the cylinders into the housing and have driving connectionwith a pair'of cam discs as 7l71 mounted upon the drive shaft so thatoperation of the pistons as 72 within the cylinders will cause rotationof the cam discs and conse uent rotation of the shaft 53.

ny suitable means, such as the feather 73 may be employed for insuringrotation of the slide rod 51 with the shaft 53 at all times.

In Figs. 7, 8 propeller blade operating mechanism which may be employedin association with the mechanism heretofore described, and particularlyin association with the operating handles 36 or 55 above described. Inthese figures the operating handle is indicated by the referencecharacter 74. The shaft or rod by which this handle is connected withthe propeller blades for changing the pitch of the propeller blades isindicated by the reference character 75, and it is noted that while thisshaft 75 is shown as having aithreaded connection at its end with a gear76, corresponding with the gear 62 illustrated in Figs.

5 and 6, for producingan' endwise sliding movement of the shaft 7 5 tochange the pitch of the propeller blades in the manner ind:-

cated in Fig. 5, nevertheless the shaft 75 may and 9, there isillustrated a P equally well be considered as having fixed connectionwith the gear 76 to thereby produce rotary movement of said shaft withsaid gear so as to change the pitch of the pro )eller blades, after themanner illustrated in higs. 1 and 2:

The handle 74 is rotatably mounted upon the instrument board 67 or otherfixed part of the aeroplane, but in the instance illus trated it isrotatably mounted concentrically wit the gear 7 6 being shown assupported upon a hub extension 77 of said gear. It

carries a gear 7 8 which meshes with a gear 79 rotatably mounted uponthe instrument board as by means of a supporting shaft 80. The gear 79is shown as being connected with a pinion 81 which meshes with the gear76, and the shaft is provided with a suitable anti-friction device as 82to frictionally hold it, and consequently the handle 74:, in anyposition to which said handle maybe rotated.

The pinion 81 operates the gear 76 for in turn operating the shaft 7 5either to rotate said shaft or to slide said shaft longitudinal- 1y, asabove indicated.

A stationary dial as 83 may be present for indicating the position ofthe propeller blades in substantially the same manner as described withreference to the dial 65. A pointer 84 may be conveniently connectedwith the gear 79 to co-operate with the dial 8 3 in the presentinstance.

The gear 76 is shown for convenience as being of segmental form and fromone side thereof projects an arm 85 carrying a stop pin 86 at its outerend projecting into and movable along an arcuate slot 87 which isprovided in the instrument board 67. The pin 86 projects at right anglesfrom the arm 85 into the slot- 87. It is slidably mounted within aguide-way 88 provided to receive it at the outer end of the arm and isyieldably urged into the slot as by a leaf spring 89 which is fixed tothe arm as at 90 by one of its ends and which has its opposite endengaging within a suitable notch as 91 of the The-pin 86 is thus alwaysnormally held within the slot so that the possible movement of the gear76 about its rotary axis is posi tively limited in both directions byengagement of the pin with the end walls 92 and 93 of the slot. 7

It will be seen that unless other means than as thus far described beprovided, the operator, by movement of the handle 7 4., would be unableto rotate the gear 7 6 beyond the limits defined by the walls 92 and 93,and it is here pointed out that this amount of move ment is intended tobe that amount which is within what may be termed safety limits. Theoperator may readily adjust his propeller blades to any desired angle asmay appeal to him within these limits but if he wishes to adjust theblades into any greater or difier- 1 ent angular position than ispermitted within these limits he must necessarily perform a further anddefinite operation, as will now be referred to. v

Carried upon the handle 74 is a lifter 94 slidably mounted within atransverse bore 95 at the end of said arm 74 and connected with thefinger grip 96 of said arm. A spring as 97 is shown for-urging thislifter, and hence the finger grip, always inwardly toward the instrumentboard 67, but the operator may at any time, by drawing outwardly uponthe finger grip, move the lifter outwardly away from the instrumentboard.

The lifter has a laterally projecting nose 98 at its inner end which isadapted to ride freely through a notch 99 of the stop pin 86 wheneverthe handle is swung past said pin in either direction.

By this arrangement it will be seen that when the handle 74.- is inposition overlying the arm 85, then, and then only, the operator, bydrawing out upon the finger grip 96, may lift the stop pin 86sufliciently far so as to pass over the end wall 92 of the slot 87.

It will be noted that although the handle may traverse the armrepeatedly while the arm is in different positions yet the gearconnections between the handle and the arm are intended to be such thatthe handle will overlie the arm, and the nose 98 will engage within thenotch 99, always at the proper time to enable the stop pin to be liftedover the end wall 92 as both the handle and the arm move in acontra-clockwise direction (Fig. 7), the stop pin being dropped again bythe nose 98 beyondsaid wall 92 as the handle continues to rotate awayfrom the arm.

Spacedbeyond the wall 92 a second wall 100 is provided-in the path ofmovement of the stop pin adapted to define a maximum limit to which saidpin may move under any circumstances.

Referring to the illustration Fig. 9, it may be correctly stated thatthe two opposite walls 93 and 100 are the opposite end walls of a singleslot and define the extreme limits of movement of the stop pin, and thatthe wall 92 constitutes in effect a shoulder intermediate said end wallsfor confining the movements of the stop pin within restricted limitsunder normal conditions. 4

It is noted that the wall or shoulder 92 is of less height than thewalls 93 and 100. The stop pin may be lifted over the wall or shoulder92 but it may not be lifted over either ofthe walls 93 or 100.

While the position of the arm may in practice be at any desired pointfor a given angular thrust position of the propeller blades, yetpreferably it is intended that when said arm is in position adjacent tobut spaced from the shoulder 92 then the propeller blades stand at whatmay be termed a normal running angle. If the'operator desires his bladesto stand in more nearly a feathering position, that is a osition of essangle, he operates the handle 4 to move the arm into a position nearerto the shoulder 92, a position against said shoulder being the limit towhich he can-move without. racing his engine. If the operator, on theother hand, desires his blades to stand in a position of relativelygreater angle, as for instance he will probably desire to do after theaeroplane has reached a rarefied atmosphere, he operatesthe handle 74 inan opposite, or clockwise, direction Fig. 7, to move the arm in adirection away from the shoulder 92 more or less according to thedictates of his will.

Movement of the arm 85 in a contra-clockwise direction over the shoulder92 first brings the propeller blades into a feathering position andcontinued movement brings them into an opposite angular position therebyapplying a brake, or reverse wind pressure, to retard movement of theaeroplane more or less according to the greatness of the reverse angleand speed of the engine, the maximum reverse angle being of course whenthe stop pin engages the wall 100.

This provision for applying a reverse wind pressure or brake againstmovement of the aeroplane may be useful at different times butisparticularly so just when and following the time when the aeroplanetouches the groundin landing. A skillful manipulation of the propellerblades at this time may bring the aeroplane to a perfect and quick stop.

It is a purpose of this invention to prevent movement of the propellerblades into, or too near to, a feathering position except when thepropeller is being driven at a rela tively reduced speed. To this endthe drawings herewith, see Figs. 7 to 9, suggest that the enginethrottle rod as 101 may be provided with an extension 102-projectinginto such relation with the arm 85 as to prevent movement of said arm inacontra-clockwise direction beyond the shoulder 92 except when thethrottle is in a slow position. I The throttle extension 102 is shown asan armate plate mounted slidably within an arcuate slot 103 formedthrough the instrumentboard 67 and having a surface 104 at its outer endarranged to be engaged by a finger 105 which projects radially from thearm 85 in such relation that said arm 85 can not be moved beyond thewall 92 unless the throttle extension or plate 102 be first withdrawnout of the path of movement of the finger.

By this arrangement the operator is required to move his throttle intoslow position thereby slowing down the rotation of the propeller, beforehe is able to move the propeller blades beyond the angular positiondefined by the stop 92.

It is ar-further purpose of this invention to automatically insure areduction of the engine speed if for any reason the operator shouldattempt to. adjust the propeller blades into a feathering or reverseposition without having previously manually reduced the en gine speed,and to this end the drawings herewith suggest that the surface 104 whichis provided upon the throttle extension for engagement by the finger2105 of the arm shall be shaped and disposed to constitute a cam withrespect to the movement of the finger 105 so that pressure of saidfinger against said surface will cam, or push, the throttle into slowposition as the stop pin 86 moves over and beyond the shoulder 92. Inthis manner the manual efi'ort of the operator, exertedupon the handle74, to adjust his propeller blades into a feathering or reversedposition will be effective to move the propeller blade as intended, butit will at the same time automatically effect a reduction'in the speedof the engine.

It is a further purpose of this invention to insure against thelikelihood of too great an engine speed when the propeller blades are ina reversed angular position, and to this end the drawings suggest thatthe throttle extension or plate 102 shall provide an end edge sur'- face106, continuing in a contra-clockwise direction, Fig. surface 106 beingadapted to stand beneath the finger 105 whenever the propeller bladesarein a reversed position and being co-operative with said finger 105 tonormally prevent movement of the throttle sufliciently far to produce ahigh speed condition of the engine. Note that in. the developmentillustrated in Fig. 9-the path of travel of the finger 105, as indicatedby the dot and dash line 107, is relatively above the surface 106 sothat it would be impossible to move the throttle rod into the positionin which it is shown if the finger 105 were moved over to overlie thesurface 106.

By this means, whenever the operator has moved his propeller blades intoa reversed position he will find that any effort which hemay make tospeed up his engine beyond a predetermined degree will be definitelyopposed by engagement of the surface 106 against the finger 105, a

The relation of the surface 106 to the finger 105 is such that it willpermit of a sufiicient speed of the engine so as to enable an operator,if his engine be dead, to start the engine, but it will not normallypermit of any considerable speed except when, or until, the finger hasbeen moved clockwise beyond the shoulder 92, and the propeller bladesthereby brought into a proper thrust applying pos1- tion for normalflymg.

It may be here noted however that the throttle fed as illustratedincludes. a resilient,

or compressible, element 108, between its handle 10!) and the workingendor extension plate 102, whereby if desired the Operator 7, from thecam surface 104:, said may be able to operate the handle 109 into a highspeed position without a corresponding movement of the surface 106.Thus, as inan emergency, the operator may speed up his propeller tomaximum at any time even though the blades be in -reversed position.

The compressible element 108 may take any desired form, but as hereinillustrated it consists in a simple cylindrical casing 110 having aplunger 111 movable therein against the compression of a coil spring112, the easing being connected with the portion 101 of the throttle rodand the plunger being con nected with the extension part or plate 102.It is a further purpose of this invention to provide means forautomatically limiting the speed at which the engine may normally be runin proportion to the angular position of r the propellerblades,particularly when said blades are in a reversed position. To this endthe drawing, Fig. 9, suggests that the surface 106, instead of being astraight line parallel with the line 107, shall be. curved with respectto said line 107, being relatively further from said line at apointadjacent the end wall and approaching relatively nearer to saidline, and then again curving away from said linetoward the opposite endof said surface. By this arrangement it will be seen that the distanceto which the surface 106, and hence the throttle, may be moved towardhigh speed position will be limited at different stages dependent uponthe position of the finger 105. If the finger be at a pointsubstantially mid-way between the shoulder 92 and the wall 100 thethrottle may be moved to a fairly high speed position, but if the finger105 be moved toward the shoulder 92 or toward. the wall 100 the speed ofthe engine will be necessary less in proportion to the distance ofmovement of the finger toward said'shoulder or wall as the case may be.

Obviously the surface 106 may be curved or s? aped to any appropriatecontour as may be best calculated to produce a proper speed limitposition of the propeller blades, and obviously also it may be extendedso as to underlie and co-operate with the finger 105 when the blades arein a forward, or non-reversed, positionif desired.

It is a further purpose of this invention to provide means automaticallyoperable to adjust the angular position of the propeller blades inaccordance with the altitude of the 1' for the engine incident to anygiven angular V sure is increased or diminished. As the vehiof thepinion 81 and produce rotation of.

said pinion to a greater or less extent ac cording to the amount towhich the rod 115 is lifted. The segment 116 stands normally out ofengagement with the pinion 81 so as not to interfere with the manualadjustment of the propeller blades at any time while the vehicle is ator near the earths surface. As the vehicle ascends into the rarefiedatmosphere however the segment will engage the pinion and continuedascent of the Vehicle will automatically cause the. segment to move thearm 85 toward the wall 93 and thereby increase the angular thrust of thepropeller blades in amount dependent upon the altitude of the vehicle.

. It is noteworthy that the mechanism described for automaticallychanging the pitch of the propeller blades as the vehicle ascends abovethe earth is of a flexible or elastic character such that it will, in anemergency,

permit of easy manual adjustment of the blades, by means of the handle74, into any desired position at any time.

A suitable-dial as 119 is preferably provided concentric with the axialpivot of the arm 85, and co-operat-ive with the finger 105, to'graphically show to the operator the position of the propeller blades atall times.

The dial 83 heretofore described co-operates with the dial 119 as aVernier device, the dial 119 giving a relatively coarse indication ofthe position of the propeller blades, and the dial 83 giving a finerindication of the position of said blades.

As many changes could be made in this construction without departingfrom the scope of the invention as defined in the fol lowing claims, itis intended that all matter contained in the above description, or shownin the accompanying drawings, shall be interpreted as illustrative onlyand not in a limiting sense.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is p 1. An adjustable propeller mechanism forvehicles, said mechanism including a plurality of propeller bladesarranged to project radially in different directions from the propellershaft of the vehicle and independently connected with-said shaft torotate upon axes transverse of said propeller shaft, operating meansextending from said blades to another portion of the vehicle by which torotate said blades in unison upon their respective axes for changing thepitch of said blades at the will of the operator, and resilient meansconnected with said blades operable to hold said blades under tensionwhen sald blades are moved by said operating means.

' 2. An adjustable propeller mechanism for vehicles, said mechanismincluding a plurality of propeller bladesiarranged to project radiallyin different directions from the propeller shaft of the vehicle andindependently connected with said shaft to rotate'upon axes transverseof said propeller shaft, operating means extending from said blades toanother portion of the vehicle by which to rotate said blades in unisonupon their respective axes for changing the pitch of said blades at thewill of the operator, and spring means interengaging between saidpropeller blades respectively and a part fixed to the propeller shaft soas to be tensioned by rotary movement of the blades.

3. An adjustable propeller mechan sm for vehicles, said mechanismincluding a plurality of propeller blades arranged to project radiallyin different directions from the propeller shaft of the vehicle andindependently connected with said shaft to rotate upon axes transverseof said propeller shaft. op-' erating means extending from said bladesto another portion of the vehicle by which to rotate said blades inunison upon their respective axes for changing the pitch of said bladesat the will of the operator, and spring means interengaging oetween saidpropeller blades respectively and a part fixed to the propeller shaft,said spring means normally holding the blades in one position but being'yieldable to permit and resist movement of the blades in oppositedirections with respect to said normal position.

4; An adjustable propeller mechanism for vehicles, said mechanismincluding a plurality'of propeller blades arranged to project radiallyin different directions from the propeller shaft of the vehicle andindependently connected with said shaft to rotate upon axes transverseof said propeller shaft, operating means extending from said blades toanother portion of the vehicle by which to rotate said blades in unisonupon their respective axes for changing the pitch of said blades at thewill of the operator, a pair of springs. interengaging betweensaid'propeller blades re spectively and a part fixed to the propellershaft, said pair of springs being operable one to urge the propellerblade in one direction and the other being operable to urge the propeller blade in an opposite direction, and means to definitely definethe normal intermediate position of the blade.

5. An adjustable propeller mechanism for vehicles, said mechan smincluding a plurality of propeller blades arranged to project radiallyin different directions from the propeller shaft of the vehicle, aplurality of stud shafts fixed to the propeller shaft radiatingtherefrom one for the attachment of each blade, said blades and saidstud shafts having parts co-operative by which the blades are rotatablymounted upon said stud shafts upon axes transverse of the propellershaft, operating means extending from said blades to another portion ofthe vehicle by which to rotate said blades in unison upon theirrespective stud shafts for changing the pitch of said blades at the willof the operator, and spring means interengaging between said blades andsaid stud shafts normally holding said blades in a given position ofadjustment but yieldable to permit forced movement of said blades inboth rotary directions with respect to the normal position of saidblades.

6. An adjustable propeller mechanism for vehicles, said mechanismincluding a plurality of propeller blades arranged to project radiallyin different directions from the pro peller shaft of the vehicle, aplurality of stud shafts fixed to the propeller shaft radiatin therefromone for the attachment of eac 1 blade, said blades and said studs havingparts co-operative by which the blades are rotatably mounted upon saidstud shafts upon axes transverse of the propeller shaft, operating meansextending from said blades to another portion of the vehicle by which torotate said blades in spective stud shafts for changing the pitch ofsaid blades at the will of the operator, a pair of coil springs mountedupon each stud shaft each spring having one end connected the two withthe adjacent propeller blade, springs upon .each stud shaft being woundin opposite directions away from the point of connection with the bladeand having their opposite ends fixed to the stud shaft'so that saidsprings thereby exert a tendency to move the blade in oppos tion to eachother about the respective stud shaft, and means carried by therespective stud shafts and engaging said springs to determine the normalPOSI- tion of the blades while permitting forced movement of the bladesand consequent tensioning of the springs by operation of said operatingmeans.

7. In combination, an engine having a drive shaft and a propellerconnected with said drive shaft 'to be rotated by the engine, means bywhich the propeller blades are pivotally mounted for adjustment intodifferent angular positions upon axes transverse to the length of theshaft, and actuating means for adjusting said blades including a rodextending through said engine concentric with the axis of rotation ofthe engine shaft and continuing beyond theend of said shaft and having apart lapping back. about the outer surface of said shaft into engagementwith said blades.= a

.8. The combination with a propeller having adjustable blades, ofcontrolmechanism for unison upon their resaid blades including parts manuallyoperable' to move the blades beyond safe limits, and means to define thesafe limits and prevent unintentional movement of the blades beyond saidlimits.

9. An adjustable propeller mechanism for vehicles, said mechanismincluding a plurality of propeller blades arranged to project radiallyin. different directions from the propeller shaft of the vehicle, aplurality of stud shafts fixed to the propeller shaft radiatingtherefrom one for the attachment of each blade said blades and said studshafts having parts co-operative by which the blades are rotatablymounted upon said stud shafts upon axes transverse of the propellershaft, operating means extending from said blades to another portion ofthe vehicle by which to rotate said blades in unison upon theirrespective stud shafts for changing the pitch of said blades at the willof the operator, spring means interengaging between said blades and saidstud shafts normally holding said blades in a given position ofadjustment but yieldable to permit forced movement of said blades inboth rotary directions with respect to the normal position of saidblades, and means to definitely define the normal position of theblades.

10. An adjustable propeller mechanism for vehicles, said mechanismincluding a plurality of propeller blades arranged to project radiallyin different directions from the propeller shaft of the vehicle, aplurality of stud shafts fixed to the propeller shaft radiatingtherefrom one for the attachment of each blade, said blades and saidstud shafts having parts co-operative by which the blades are rotatablymounted upon said stud shafts upon axes transverse of the propellershaft, operating means extending from said blades to another portion ofthe vehicle by which to rotate said blades in unison upon theirrespective stud shafts for changing of said blades at the will of theoperator, spring means interengaging between said blades and said studshafts normally holding said blades in a given position of adjustmentbut yieldable to permit forced movement of said blades in both rotarydirections with respect to the normal position of said blades, and meanscarried by each stud shaft co-operative with said spring means todefinitely define the normal position of the blades.

11. An adjustable propeller mechanism for vehicles. said mechanismincluding a plurality of propeller blades arranged to project radiallyindifferent directions from the propeller shaft of the vehicle, aplurality of stud shafts fixed to the propeller shaft radiatingtherefrom one for the attachment of the pitch each blade, said bladesand said stud shafts to another portion of the vehicle by which to uponaxes transverse of the propeller shaft, operating means extending fromsaid blades rotate said blades in unison u on their respective studshafts of said blades at the will of the operator, spring meansinterengaging between said blades and said stud shafts normally holdingposition of adjustment said blades in a given but yieldable to permitforced movement of said blades in both rotary directions with respect tothe normal position of said-blades, and means carried by each stud shaftprojecting therefrom into engagement with said spring means todefinitely define the normal position of the blades.

12. An adjustable propeller mechanism for vehicles, said mechanismincluding a plurality of propeller blades arranged to project radiallyin different directions from the propeller shaft of the vehicle, aplurality of stud shafts fixed to the propeller shaft radiatingtherefrom one for the attachment of each blade, said blades and saidstud shafts having parts co-operative by which the blades are rotatablymounted upon said stud shafts upon axes transverse of the propellershaft, operating means extending from said blades to another portion ofthe vehicle by which to rotate said blades in unison upon theirrespective stud shafts for changing the pitch of said blades at the willof the operator, sprin means interengaging between said blades an saidstud shafts normally holding said blades in a given position ofadjustment but yieldableto permit forced movement of said blades in bothrotary directions with respect to the normal position of said blades,and means fixed rigidly upon each stud shaft and having co-operativeengagement with said spring means to definitely define the normalposition of the blades.

13. The combination with a propeller having adjustable blades, ofcontrol mechanism for said blades including parts manually 0perable toadjustably move the blades, means to normally restrict the movement ofsaid blades within given limits, and means manually operable to effect amovement of the blades beyond said limits at the will of the operator.

14. The combination with a propeller having adjustable blades, ofcontrol mechanism for said blades including parts manually operabletoadjustably move the blades, means to normally restrict the movement ofsaid blades within given limits, means manually operable to effect amovement of the blades beyond said limits at the will of the operator,and means to-insure a slow speed condition of the propeller when theblades are adjusted beyond said given limit.

15. The combination with a propeller having adjustable blades, ofcontrol mechanism for said blades including parts manually opforchanging the pitch the erable to adjustably move the blades, means tonormally restrict the movement of said blades within given limits, meansmanually operable to effect a movement of the blades beyond said limitsat the will ,of the operator, and means effective to produce a slowspeed condition of the propeller incident to move ment of the bladesbeyond said given limits.

16. The combination with a propeller having adjustable blades and drivemeans for said propeller, of control mechanism for said blades includingparts manually operable to adjustably move the blades, means to normallyrestrict the movement of said blades within given limits, means manuallyoperable to efiect a movement of the blades beyond said limits at thewill of the operator, and means to insure a slow speed condition ofpropeller when the blades are adjusted beyond said given limits,together with means manuallly operable in an emergency to increase t espeed of the propeller when the blades are adjusted beyond said givenlimits.

17 The combination with a propeller havingadjustable blades and drivemeans for said propeller, of control mechanism for said blades includingparts manually operable to adjustably move the blades into various for-Ward and reverse angular positions, and means to control the speed ofthe propeller in accordance with the angular position of the blades.

, 18. The'combination with a propeller having adjustable blades anddrive means for 100 said propeller, of control mechanism for said bladesincluding parts manually operable to adjustably move the blades intovarious forward and reverse angular positions, and means to insure aslow speed condition of the 105 propeller when the propeller is in areverse angular position.

19. The combination with a propeller having adjust-able blades, ofcontrol mechanism for said blades including a longitudinally 110 movablecontrol rod, manually operable means to slide said rod for adjustablymoving the blades into various angular positions, and meansautomatically operable to slide said rod for adjusting the bladesdependent 1 5 upon the altitude of the mechanism.

20. The combination with a propeller having adjustable blades, ofcontrol mechanism for said blades including parts manually operable toadjustably move the blades into v'a- 120 rious angular positions, andmeans normally disconnected from the blades but automaticalature.

ING.

